OpenPGP_SignaturePacket::issuer PHP Method

    function issuer()
    {
        foreach ($this->hashed_subpackets as $p) {
            if ($p instanceof OpenPGP_SignaturePacket_IssuerPacket) {
                return $p->data;
            }
        }
        foreach ($this->unhashed_subpackets as $p) {
            if ($p instanceof OpenPGP_SignaturePacket_IssuerPacket) {
                return $p->data;
            }
        }
        return NULL;
    }